Ductless fan assembly

ABSTRACT

A ductless ventilation system for removing air from a living space, treating the air, and discharging the air back into the living space. The ductless ventilation system includes a fan housing defining an internal space, a blower arranged within the internal space, and a filter system including a plurality of filters each being selected to condition the air in a different way from one another.

PRIORITY

This Application claims benefit under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 63/114,057, filed Nov. 16, 2020, which is expressly incorporated by reference herein and made a part hereof.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The detailed description particularly refers to the accompanying figures in which:

FIG. 1 is a side elevation and diagrammatic view of a ductless ventilation system with portions removed to show various features of the ductless ventilation system; and

FIG. 2 is a perspective view of the ductless ventilation system of FIG. 1.

DETAILED DESCRIPTION

A ductless ventilation system 10, in accordance with the present disclosure, is shown in FIG. 1 as including a fan housing 20, a blower 30 located within an internal space 22 defined by the fan housing 20, and a filter system 40 disposed within the internal space 22. The fan housing 20 may be mounted to one or more structures, such as joists above a ceiling 24, surrounding a living space of a building (not shown). The blower 30 is configured to circulate air from the living space into the internal space 22 of the fan housing 20 through an inlet port 26 defined in the fan housing 20, then through the filter system 40, and then returned to the living space through an outlet port 28 defined in the fan housing 20. The filter system is configured and arranged to condition the air before returning the air back to the living space.

The internal space 22 defined by the fan housing 20 may be divided into a plurality of sub-spaces such as a blower compartment 32 that contains the blower 30, and a filter compartment 42 that contains one or more filters of the filter system 40 as shown in FIG. 1. The inlet port 26 opens into the blower compartment 32 to admit unconditioned air containing contaminants, such as humidity, odors, and/or particles, into the internal space 22 when the blower 30 is in operation. The unconditioned air is directed from the blower compartment 32 toward the filter compartment 42 where it passes through one or more filters to condition the air as will be described in greater detail below. The conditioned air then exits the filter compartment 42 through the outlet port 28 to return conditioned air to the living space. A fan grille 44 may cover the inlet port 26 and the outlet port 28 to obstruct view from the living space into the internal space 22 of the fan housing 20 as shown in FIG. 2.

The blower compartment 32 may be separated from the filter compartment 42 by a barrier 43. The barrier 43 defines an opening 45 that allows passage of the air from the blower compartment 32 to the filter compartment 42. The embodiment depicted in FIG. 1 comprises a filter system 40 having a first stage filter 46, a second stage filter 48, and third stage filter 50. In one embodiment, each of the filters 46, 48, 50 may be different from the others to remove different types of contaminants that may be present in the air from the living space.

The first stage filter 46 is a pre-filter that is configured to trap and remove relatively larger particles of contaminants, such as dust, aerosol particles (hair spray, etc), dander, etc., from the air entering the fan housing 20 through the inlet port 26. These larger contaminants are removed from the air prior to air reaching the blower 30. Removal of the larger contaminants as the air enters the fan housing 20 prevents the contaminants from adversely affect performance of the blower 30 and additionally allows for filtering of smaller contaminants by the second stage filter 48 and third stage filter 50. The first stage filter 46 may be constructed of a mesh, spun fiber, or other suitable media for removing relatively larger particles of contaminants from the air. The first stage filter 46 may be positioned in the inlet port 26 or within the fan grille 44 upstream of the blower compartment 32 such that it can be easily accessed from the living space for periodic maintenance and cleaning to maintain proper airflow. In some embodiments, the first stage filter 46 may include an anti-microbial coating to block unwanted growth of mold and/or fungus. In an alternative embodiment, the first stage filter 46 could be located downstream of the blower 30 (e.g. in the filter compartment 42).

The second stage filter 48 may comprise an absorbent desiccant media bed that is configured to attract and collect water vapor generated by showers, baths, etc. and entrained in the air that enters the internal space 22. As such, the second stage filter may only be subject to a contaminant event for short periods of time (i.e. the duration of a shower). The second stage filter 48 is located within the filter compartment 42 downstream of the blower compartment 32. If the barrier 43 is included, the second stage filter 48 may be located in the opening 45 so that all of the air from the blower compartment 32 passes through the second stage filter 46.

The third stage filter 50 may be configured to absorb and remove volatile organic compounds (VOCs) from the air passing through the internal space 22 before the air is directed back into the living space. The third stage filter 50 may comprise an activated carbon filtration bed that may include one or more additives (i.e. silver, potassium permanganate, etc.), a UV lamp, a catalytic filter (i.e. TiO2), or any other additive or device to aid in purification and/or sanitization of the air prior to releasing the air into the living space.

The ventilation system 10 may further include a control system 60 that is configured to control operation of the blower 30 and other components of the ventilation system 10 depending on various situations. The control system 60 includes a microprocessor 62, a memory-storage device 64, and one or more sensors 66. The microprocessor 62 provides all of the functionality needed to operate the ventilation system 10 in response to signals received by user inputs and/or sensor signals from the one or more sensors 66. The memory-storage device 64 includes a stored set of instructions that, when executed by the microprocessor 62, causes the ventilation system 10 to enter into one or more modes in response to the various signals received. The one or more sensors 66 are configured to send signals to the microprocessor 62 that are indicative of various properties of the air in the living space and/or the internal space 22 such as, humidity, temperature, density, and VOC levels. These properties may be determined by the control system 60 directly from sensor signals and/or from other conditions of the filters 46, 48, 50.

The one or more sensors 66 may be used to determine if the first stage filter 46 is in need of cleaning, maintenance, or replacement. For example, the sensor(s) 66 may provide signals to the microprocessor 62 that correspond to a measurable property or condition of the first stage filter 46 or the air passing through the first stage filter 46. The microprocessor 62 may issue a command signal to cause an alert in response to the signals reaching a predetermined threshold to notify a user when the first stage filter 46 is in need of cleaning, maintenance, or replacement. The alert may be in the form of a local indicator relative to the ventilation system 10, such as a visible light or an audible alarm, or a remote indicator relative to the ventilation system 10, such as a message to a device (i.e. a smart phone). Some suitable types of sensors 66 that could be used to measure the property or condition of the first stage filter 46 and/or the air passing through the first stage filter include a pressure sensor, a flow sensor, and a timer.

The control system 60 may operate the blower 30 and the filter system 40 in a moisture-removal mode during a high-moisture event in which the blower 30 is activated to displace air through the second stage filter 48 to remove water vapor from the air. Once the high-moisture event has concluded, the control system 60 may operate the blower 30 in a moisture-release mode to draw the water vapor from the second stage filter 48 into relatively drier air over a period of time such that occupants within the living space do not notice changes in humidity levels (i.e. a gradual increase). The microprocessor 62 may activate and deactivate the water-vapor removal mode and the moisture-release mode automatically based on signals from the sensor(s) 66.

The control system 60 may continue operation of the blower 30 at a maximum or a lower output to control release of water vapor from second stage filter 48. The blower 30 may be deactivated by the control system 60 once humidity levels reach equilibrium or comfortable levels. In some embodiments, a heating element 52 may be located upstream of the second stage filter 48 and activated by the control system 60 to increase the temperature of the air, thus increasing the moisture the air is capable of holding. Selective heating the air in this manner and selective operation of the blower 30 allows for a controlled release of the water vapor from the second stage filter 48 over time. The heating element 52 may be an electrically conductive coil or a thermoelectric module that is connected to a power source (not shown). In some embodiments, a heat sink and evaporator tray could also be included in the second stage filter 48 to help collect fluid that has condensed on the second stage filter 48 or other parts of the ventilation system 10. Air from the blower 30 passing over the evaporator tray may slowly release the water vapor back into the living space over time.

The control system 60 may set a schedule to time the release of the water vapor back into the living space at when there is no occupancy, such as at night or another convenient time. For example, a motion sensor could be included in the sensor(s) 66 to determine occupancy in the living space. The control system 60 may activate the moisture-release mode after a predetermined amount of time has passed without any detected motion. Alternatively, the control system 60 could track cycles of humidity throughout the day and be scheduled to release water vapor back into the living space during drier times of day. In yet another alternative, the control system 60 continuously measures the humidity in the living space and releases water vapor back into the living space whenever the humidity in the living space falls below a predetermined threshold.

The ventilation system 10 may optionally include a shutter 70 that divides the filter compartment 42 into a second-stage region 80 comprising the second stage filter 48 and a third-stage region 82 comprising the third stage filter 50. An actuator 72 is controlled by the control system 60 and configured to open and close the shutter 70. When the shutter 70 is in a closed position, air leaving the second stage filter 48 is blocked from entering the third stage filter 50 and instead exits the internal space 22 through a first sub-outlet 84. When the shutter 70 is in an opened position, air is free to pass through the third stage filter 50 and exits the internal space 22 through a second sub-outlet 86. The control system 60 may selectively operate the actuator 72 to open or close the shutter 70 depending on VOC levels measured in the air from one or more sensors included in sensor(s) 66. For example, if the sensor(s) 66 determine a high-moisture event but low or no VOC's, the shutter 70 may be closed such that only the first stage filter 46 and second stage filter 48 are utilized. If VOC levels reach a threshold, the shutter 70 may be opened to utilize the third stage filter 50. Including the shutter 70 may prolong the useful life of the third stage filter 50. In another alternative embodiment, the shutter 70 may be closed while the control system 60 is operating the fan to release moisture from the second stage filter 48, but low or not VOC's are detected.

In some embodiments, the internal space 22 may be further divided by other barriers or shutters/valves that open and/or close to establish other flow paths to direct the air to a tailored filter for the particular event sensed by sensor(s) 66. Additionally, sensor data could be used to adjust a speed of the blower 30 to allow improved capture of the contaminants or, in conjunction with one or more shutter or valve configurations.

The ventilation system 10 is well suited to be used in place of a traditional bathroom exhaust fan. The ventilation system 10 depicted in FIG. 1 and FIG. 2 embodies a traditional exhaust fan. The ventilation system 10 is also well suited to be used over a cook top, such as in a range hood. When configured for use over a cook top, the sensor and filtration capabilities and capacities may vary from a bathroom exhaust fan since the detection and removal of VOCs can be relatively more important than detection and removal of humidity. In an embodiment of a ventilation 10 configured for a cook top, a heat sink (not depicted) may replace the heating element 52 in order to remove heat from circulated air in a manner permitting easier filtration of the air or lessening degradation of the filters.

In all embodiments, the ventilation system 10 is configured to permit removal and replacement of the filters. 

1. A ductless ventilation system for removing air from a living space, treating the air, and discharging the air back into the living space, comprising a fan housing defining an internal space, a blower arranged within the internal space, and a filter system including a plurality of filters each being selected to condition the air in a different way from one another.
 2. The ductless ventilation system of claim 1, wherein the internal space is divided into a plurality of sub-regions to house one or more of the plurality of filters and at least one of the plurality of filters is selectively isolated from the air such that the air does not pass therethrough.
 3. The ductless ventilation system of claim 2, further comprising a shutter configured to isolate the at least one of the plurality of filters from the air and a control system configured to selectively open and close the shutter in response to types or amounts of contaminants in the air. 